CARB also voted to expand its efforts to promote electric cars, including "paving the way for new regulations to rapidly increase the number of zero-emission vehicles required to be sold in California after 2025," according to an agency press release.

California politicians have indicated a willingness to lead the resistance against President Trump on a variety of legislative fronts, but Friday's CARB vote is likely the most aggressive move yet in terms of environmental and transportation policy.

"Today ARB affirmed the technical reviews done by our own and EPA staff, as well as the work of independent analysts," chair Mary Nichols said of the vote.

"The Air Resources Board's re-commitment to ZEVs means the state is getting closer to a day when all Californians can breathe clean air," said Kathryn Phillips, director of the Sierra Club in California.